Solid metals or alloys generally possess crystalline structures but if a molten metal is quenched rapidly (the cooling rate is approximately 10.sup.4 .degree.-10.sup.6 .degree. C./sec), a solid having a non-crystalline structure, which is similar to a liquid structure and has no periodic atomic arrangement, is obtained. Such metals or alloys are referred to as amorphous metals or alloys. In general, metals of this type are alloys consisting of two or more elements and can be classified into two groups, generally referred to as metal-metalloid alloys and inter-metal (metal-metal) alloys.
As the former embodiment, Fi-Ni-P-B (Japanese Patent Laid-Open Application No. 910/74), Fe-Co-Si-B (Japanese Patent Laid-Open Application No. 73,920/76) and the like have been known.
As the latter embodiment, only U-Cr-V (Japanese Patent Laid-Open Application No. 65,012/76) has been recently reported except for Zr.sub.60 Cu.sub.40, Zr.sub.78 Co.sub.22 and the like which were reported previously. Particularly, as amorphous alloys of a combination of iron group elements and Group IVB, VB elements which contains less than 50 atomic % of Group IVB or VB elements, only Nb.sub.100-x Ni.sub.x (x: 33-78) and Zr.sub.100-x Ni.sub.x (x: 40-60) have been known.
Already known amorphous metals of combinations of iron group elements and metalloids, for example, Fe-P-C or Fe-Ni-P-B have excellent properties in view of strength, hardness, magnetic properties and the like. However, the structure of these alloys is unstable, so that the properties vary considerably during aging, and this is a great practical drawback. In addition, it has been known concerning heat resistance that embrittlement occurs even at a lower temperature than the crystallization temperature as well as at a higher temperature than the crystallization temperature. This phenomenon is presumably based on the fact that the atomic radius of the metalloid element contributing to the amorphous formation is smaller than that of the iron group elements and diffusion of the metalloid atom takes place easily in these alloys.
On the other hand, in metal-metal amorphous alloys, it has been known that the content of elements having a small atomic radius is not large, so that embrittlement at a lower temperature than the crystallization temperature seldom occurs. Even at a higher temperature than the crystallization temperature, the extent of embrittlement of these amorphous alloys is smaller than that of metal-metalloid amorphous alloys.
However, previously reported metal-metal amorphous alloys contain a large amount of Group IVB and VB elements (Ti, Zr, V, Nb, Ta), so that the cost of the raw materials is very high, the melting point of those alloys is high and the molten metal is easily oxidized, therefore the production of these amorphous alloys is very difficult. Thus there is a disadvantage with difficulties in production of ribbon, sheet and wire in good shapes which can be utilized for practical usages in industries. Furthermore, a problem exists that the strong ferromagnetic property which is characteristic to iron group elements is lost.
An object of the present invention is to provide metal-metal amorphous alloys in which the above described drawbacks and problems of already known metal-metalloid amorphous alloys or metal-metal amorphous alloys are obviated and improved.